2022-03-21 22:46:53 +05:30
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[metadata]
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creation_date = "2022/03/17"
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2022-05-25 08:32:53 +05:30
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deprecation_date = "2022/05/09"
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maturity = "deprecated"
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updated_date = "2022/05/09"
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2022-03-21 22:46:53 +05:30
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[rule]
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author = ["Elastic"]
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description = """
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Identifies Linux binary cpulimit abuse to break out from restricted environments by spawning an interactive system
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shell. The cpulimit utility is used to restrict the CPU usage of a process in cases of CPU or system load exceeding the
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defined threshold and the activity of spawning a shell is not a standard use of this binary by a user or system
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2022-05-25 08:32:53 +05:30
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administrator. This can potentially indicate a malicious actor attempting to improve the capabilities or stability of
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their access.
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2022-03-21 22:46:53 +05:30
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"""
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from = "now-9m"
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index = ["logs-endpoint.events.*"]
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language = "eql"
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license = "Elastic License v2"
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name = "Linux Restricted Shell Breakout via cpulimit Shell Evasion"
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references = ["https://gtfobins.github.io/gtfobins/cpulimit/"]
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risk_score = 47
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rule_id = "0968cfbd-40f0-4b1c-b7b1-a60736c7b241"
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severity = "medium"
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tags = ["Elastic", "Host", "Linux", "Threat Detection", "Execution", "GTFOBins"]
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timestamp_override = "event.ingested"
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type = "eql"
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query = '''
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2022-04-01 15:27:08 -08:00
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process where event.type == "start" and process.name in ("bash", "sh", "dash") and
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process.parent.name == "cpulimit" and process.parent.args == "-f" and
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process.parent.args in ("/bin/sh", "/bin/bash", "/bin/dash", "sh", "bash", "dash")
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2022-03-21 22:46:53 +05:30
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'''
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[[rule.threat]]
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framework = "MITRE ATT&CK"
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[[rule.threat.technique]]
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id = "T1059"
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name = "Command and Scripting Interpreter"
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reference = "https://attack.mitre.org/techniques/T1059/"
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[[rule.threat.technique.subtechnique]]
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id = "T1059.004"
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name = "Unix Shell"
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reference = "https://attack.mitre.org/techniques/T1059/004/"
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[rule.threat.tactic]
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id = "TA0002"
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name = "Execution"
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reference = "https://attack.mitre.org/tactics/TA0002/"
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